Known systems for a vehicle including a combination electric motor and generator for driving accessories for the vehicle maintain a connection between an engine for the vehicle and the input/output shaft of the combination electric motor and generator during operation of the combination electric motor and generator as a generator, for example, when transmitting torque from a transmission input shaft to the combination electric motor and generator. However, maintaining the connection between the engine and input/output shaft decreases the efficiency of the generator operation by introducing drag from the engine.